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World Environment Day 2022: what is the role of cities?

To mark World Environment Day, here’s a concise summary of what you should know about the role that cities have to play in the race to net zero

Blog post published on 6 June 2022 by Valentine Quinio

Yesterday was World Environment Day – an initiative by the United Nations to encourage awareness and action to protect the planet. In the UK, environmental concerns and the race to net zero briefly made headlines last year, when the country hosted the COP26 summit in Glasgow. Since then, international and domestic affairs have relegated environmental issues to the background of the news and politics agenda.

But the clock is still ticking. A recent report by the Intergovernmental Panel on Climate Change (IPCC) has warned that progress towards the 2050 net zero target is too slow. From that document – and our own net zero work over the past year – here’s a summary of what you should know about the role cities have to play, and why you should care.

1. Cities are good for the environment

According to the IPCC, cities will play a decisive role in achieving net zero. They concentrate a majority of the world’s carbon emissions and are hotspots of climate impact, but they’re also a crucial part of the solution.

Our work echoes this, and goes even further: it shows that cities and large towns are better than everywhere else when it comes to reduced carbon emissions. The UK’s 63 largest cities and towns generate about 45 per cent of all emissions. But they also account for 55 per cent of the population, meaning that on a per capita basis, cities are greener. On average in the UK, a person living in a city or a large town emits about four tonnes of carbon a year, against more than six for someone living outside of these areas.

Figure 1: Cities have a lower carbon footprint

Source: BEIS, 2020.

There are two main reasons for this. The first is that high-emitting industrial activity tends to be located outside cities. The second is that carbon emissions are hugely influenced by the nature of the built environment; density encourages greener lifestyles.

The importance of cities (and density) in the race to net zero becomes particularly clear when looking at two areas: transport and housing. Emissions in these areas have remained stubbornly high in the UK in recent decades. Density facilitates active travel (because distances are shorter) and makes public transport more viable (because demand is higher). So, denser housing, like flats or terraced houses, are much more energy-efficient. This explains why transport and domestic emissions are lower in cities than elsewhere (Figure 1).

2. Getting to net zero will require reaping the benefits of density

The IPCC report points to the fact that changes in urban form, density and land use will be needed to cut emissions.

As our work shows, this is particularly true in the UK, where cities are not very dense by international standards – way less than their European counterparts. If the UK wants to reach net zero by 2050, cities will need to be denser. This will require changing the way they are planned, built and spatially managed.

Take transport, for instance. The biggest challenge to decarbonising the sector is to take people out of their cars and encourage cleaner mode of transport. Recent research has ranked the best car use reduction strategies in cities, including congestion charges, parking and traffic control, and limited traffic zones. For these schemes to be both effective and fair, they need to facilitate the use of viable alternative options, like public transport. Encouraging people to hop on a bus will be much easier if transport policy is done in conjunction with spatial planning policies – for instance by building more homes near existing public transport network, and densifying suburbs to make bus routes more viable.

3. Net zero is a global issue. But local leaders need to play their part, too

Climate change is a global challenge, and the net zero target for 2050 in the UK has been set nationally. This means the Government is responsible for it, and needs to deliver on a number of pledges, such as phasing out petrol and diesel cars by 2030 and accelerating the retrofit agenda. The IPCC report also makes very clear that getting there will require local government to also play their part and that mayors and local leaders are hugely important when it comes to tackling climate change.

In the UK, more than 300 local authorities have now declared climate emergencies but too few have pulled the levers they have at their disposal to cut carbon emissions in their local area. As local planning authorities, they can influence the spatial footprint of their area and prevent excessive urban sprawl and car-reliant developments, whether residential or commercial. As transport authorities, they can invest in cycling infrastructure, use bus franchising powers to make it more affordable and convenient, and use the powers they have to charge private cars in city centres. While it’s true that some of this may need to come with more funding and powers from Westminster, eventually city leaders will need to make tough political choices too if they want to honour their commitments to carbon reduction.